mailer.js

const nodemailer = require('nodemailer');
const { google } = require('googleapis');
const bcrypt = require('bcrypt');
const OAuth2 = google.auth.OAuth2;
const secret = require('dotenv').config();

class Mailer {
	/*
    generic handler I wrote so that i don't have to configure all this boilerplate everytime. 
    here is the tutorial about the configuration in the google cloud system.
    https://medium.com/@nickroach_50526/sending-emails-with-node-js-using-smtp-gmail-and-oauth2-316fe9c790a1 
    (currently only provide emailing thourgh gmail 
    */
	constructor(appAddress) {
		this.appAddress = appAddress;
		this.transporter = nodemailer.createTransport({
			service: 'Gmail',
			auth: {
				type: 'OAuth2',
				user: appAddress,
				clientId: process.env.GMAIL_CLIENT_ID,
				clientSecret: process.env.GMAIL_CLIENT_SECRET,
				refreshToken: process.env.GMAIL_REFRESH_TOKEN,
				accessToken: this.SetGoogleAuth()
			}
		});
	}
	async SetGoogleAuth() {
		const oauth2Client = new OAuth2(
			process.env.GMAIL_CLIENT_ID, // ClientID
			process.env.GMAIL_CLIENT_SECRET, // Client Secret
			'https://developers.google.com/oauthplayground' // Redirect URL
		);
		oauth2Client.setCredentials({
			refresh_token: process.env.GMAIL_REFRESH_TOKEN
		});
		return await oauth2Client.getAccessToken();
	}
	SendMail({ to, subject, isHTML, content, params }) {
		try {
			if (params) {
				content = this.EmbedMailParams(params, content);
			}
			this.transporter.sendMail({
				from: this.appAddress,
				to,
				subject,
				generateTextFromHTML: isHTML,
				html: content
			});
		} catch (ex) {
			throw ex;
		}
	}
	EmbedMailParams(params, content) {
		//enumrating the html, if catches {~someproperty~} then replaces with value!
		for (let prop in params) {
			if (params.hasOwnProperty(prop)) {
				//TODO: find out why string literal fucks it up..
				content = content.replace('{' + prop + '}', params[prop]);
			}
		}
		return content;
	}
}
module.exports = Mailer;